Debbie Phelps will never forget the day the best swimmer in the world moved from Baltimore. "He left on July3, 2004, went to the Olympics and never came home," she says.

"As a mom, you know they'll all leave, that they won't live with you forever," she says. "But it's still hard."

From Baltimore to Michigan to China.

Today the U.S. swim team is training in Singapore. They'll head early next week to Beijing, where the Summer Games commence Friday and Michael Phelps begins his incredible pursuit of eight gold medals.

And waiting on the other side of history: an unexpected homecoming. From Beijing back to Baltimore.

"I never dreamt that he'd come back," Debbie says.

Certainly she didn't that day four years ago. Technically, Phelps did return home after Athens. But he was so caught up in a post-Olympics tour, meeting corporate sponsors and waiting in airport terminals, that he spent little time in Baltimore.

While Phelps was basking in the world's spotlight - television cameras and teenage girls around the globe begging for just a glimpse - Debbie was left in charge of the moving process. Everything from her son's television to all of his Ravens gear was packed into boxes and loaded onto a truck.

"It was just a stormy, dismal day in Baltimore," she says. "I'll always remember that. The weather just paralleled my feelings."

In 2004, Phelps was undoubtedly Baltimore's son. He was a veteran of the ratty Orioles cap. He swam under the banner of North Baltimore Aquatic Club. He was flanked by family and friends from Maryland.

But then, weighed down by Athens gold and hopes for much more in 2008, he left Baltimore. He settled down in Ann Arbor, Mich., where his coach, Bob Bowman, took over the University of Michigan swim program. Phelps showed up at swim meets around the country wearing caps that featured Tigers and Dodgers logos. His busy schedule and stringent swimming demands had him touring the globe.

But what of home?

Any thoughts that Phelps had forgotten Baltimore can be laid to rest. After Beijing, Bowman is taking over as chief executive at NBAC, and Phelps is coming with him.

"I definitely want to live there," Phelps says of Baltimore. "Just because I love it and miss it so much."

He made that proclamation to The Sun's Kevin Van Valkenburg on a recent visit to Ann Arbor. Phelps was then asked to name three things he misses about home. He said the seafood. And the Bawlmer accent. "It's hard to really put it into three things. … I think I just miss Baltimore as a whole," he said. "Being away from a place you've been for almost 20 years, all the sudden I pick up and move? It's just completely different from Baltimore. It's so much smaller. There's not as much to do. Baltimore has everything. Anything and everything. Whenever you want, wherever you want."

But the consensus from those who know him best is that Phelps had to leave.

To get better, to mature, to dive into the Beijing pool with a chance at history, Phelps had to follow Bowman. Living in Ann Arbor allowed him to train around other elite swimmers every day, to stay near his coach and to spread his long arms and explore his independence.

"He was just a 18-, 19-year old kid, still living at home," says his sister, Whitney Flickinger. "He'd never really been outside of his comfort zone. He needed to do that for himself."

At the time, no one was sure whether Phelps would return. But that first winter, Phelps hosted his immediate family for a Christmas in Ann Arbor. He popped out of his car for just a brief moment one afternoon when he noticed ice quickly accumulated on the inside of the window.

"I remember he was standing there scraping, and he said: 'Yeah, it's really cold here. I'm not sure how long I can deal with this,'" Flickinger says "That was the first hint I had that he might someday return."

Bowman had been in discussions with NBAC for months before he accepted the position this spring. The news came as a surprise to Debbie, though.

"[Michael] just called one day," she says, "and told me, 'I'm buying a house in Fells Point.' I said, 'What? You didn't let me help?' He said, 'Don't worry, you'll love it.'"

In the days and weeks before Beijing, Phelps started thinking about how he could secure Ravens season tickets. And his mom? Just as Debbie Phelps had watched her son's possessions leave Baltimore on a truck, nearly four years later she was on the receiving end when a similar truck pulled into town.

As she unloaded the truck and unpacked a few boxes, Debbie couldn't help noticing the weather outside.

COMING SUNDAY Read about Michael Phelps' road to Beijing in Sunday'sSun. In addition, look for more Olympics coverage in Sports, including how parents helped to develop their Olympic athletes, past Olympians from Maryland and who will be representing the state in Beijing.